Electrosurgical cutting device

ABSTRACT

An improved electrosurgical cutting device for connection to an electrosurgical generator has a non-conductive support member with a peripheral edge and a conducting member in the form of a wire electrode, distinct from the support member, disposed along at least a portion of the peripheral edge of the support member. The conducting member is electrically connected to an electrosurgical generator suitable for transmitting sufficient high frequency electrical energy to the conducting member, thereby enabling the conducting member to cut body tissue. The support member has a configuration that facilitates the manipulation of body tissue either with or without the presence of electrical energy at the conducting member.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to electrosurgical electrode instruments forsurgical cutting of body tissue.

2. Technical Background

Electrosurgical instruments are used extensively in surgical practiceand the advantages to their use over conventional non-electricalsurgical instruments are well recognized in the practice. A commonapproach taken in the art of electrosurgery that is effective for bothcauterizing and cutting tissue entails the use of a monopolar circuit. Amonopolar circuit is composed of an electrosurgical generator with twooutlet connections: an active and a dispersive. The dispersive outletconnects to a dispersive pad which is attached to a patient's body. Theelectrosurgical generator sends high frequency electrical energy throughthe patient's body by means of the dispersive connection. The activeconnection is connected to an electrode which is then placed inproximity to or in contact with the body. Thus, the electrical energypresent in the body is concentrated to those specific areas in proximityto the electrode. Those cells of the body thus exposed to theconcentrated electrical energy are heated and then exploded by sparksarcing from the electrode to the cells. In this manner, the circuit iscompleted and, depending on further techniques, cauterization or cuttingis achieved.

The shape and size of the electrode may vary depending on the purpose ofthe surgery. Commonly found in the surgical practice are electrosurgicalinstruments that utilize thin, wire electrodes. Typically, the wireelectrodes are configured into needle or loop shapes. Both the needleand the loop electrodes are efficient cutters because their thinnessallows the surgeon to concentrate the electrical energy to a verylimited region of body tissue, thus fully utilizing the energy in thecutting process and preventing any unnecessary exposure to theelectrical energy where cutting or burning of tissue is not desired. Theprinciples that govern the electrosurgical cutting process are wellknown and the observation that thin wire electrodes are the best cuttersis not a surprising conclusion to any knowledgeable practitioner.

However, the wire electrodes are limited in their cutting performancedue to their lack of mechanical rigidity and their general fragilenature. This is especially true when the electrodes become hot duringthe surgical cutting process. Furthermore, it is often desirable for thesurgeon to use the cutting electrode, without current applied, as amechanical tool to separate tissues (i.e., cold or mechanicaldissection) that are adjacent to each other but which should not beexposed to the electrical energy of electrosurgical cutting. Naturally,the thin electrodes function poorly in mechanically separating bodytissue because they lack sufficient mechanical reinforcement to effectproper dissection.

An electrosurgical instrument that is conveniently used both forelectrosurgical cutting and mechanical dissection is the paddleelectrode. This elongated, flat electrode has the mechanical strength toallow mechanical dissection and is able to create sufficient currentconcentration on its edges to accomplish good electrosurgical cutting.However, compared to a needle or wire loop electrode, the paddleelectrode is a less efficient cutter because much of the high frequencyelectrical energy supplied by the electrosurgical generator flows to thebody tissue through the sides of the paddle electrode where no exposureor cutting activity is desired. In some circumstances, the currentflowing through the sides of the paddle electrode may have a beneficialeffect in cauterizing the wound created in cutting through the tissue.However, in most cases, it is a wasteful use of current resulting in anextra burden for the electrosurgical generator and requires a largerpower setting of the generator to accomplish the cut. Using a paddleelectrode also frequently results in thermal damage to the tissue alongthe cut and in troublesome sticking of tissue to the sides of thepaddle. Nevertheless, the paddle electrode has the advantages ofsuperior mechanical strength and a flat shape that acts as a ruddergiving the surgeon a better ability to guide the electrode along astraight or smooth curved line.

One attempt to solve the side conduction problem of the paddle electrodehas been to coat the sides of the paddle with plastic, typically Teflon,which diminishes the current conducted out the side and preventssticking of the tissue to the paddle electrode. This solution is onlypartially successful because at the high frequencies used forelectrosurgery, there is substantial current that is capacitivelycoupled from the metal of the paddle, through the plastic coating, andto the body tissue. Thus, a more successful and permanent solution hasyet to be realized.

From the foregoing, it will be appreciated that it would be anadvancement in the art to provide an improved electrosurgical cuttingdevice which realizes the advantages of the wire electrode and paddleelectrode and at the same time eliminating their disadvantages.Specifically, it would be an advancement in the art to provide anelectrosurgical cutting device which concentrates the electrical energyto a limited area of body tissue, yet has sufficient mechanical rigidityto allow improved cutting performance and to permit mechanicaldissection. Yet another advancement in the art is to provide a devicewith the above features which is simple and economical to manufacture.

Such an electrosurgical cutting device is disclosed and claimed herein.

BRIEF SUMMARY OF THE INVENTION

The present invention provides an electrosurgical cutting device to beused generally in all areas of surgical cutting. The present inventionparticularly contemplates the use of the electrosurgical cutting deviceas the active outlet in a monopolar circuit. The present invention isdesigned to efficiently cut body tissue through the process of celllysis using heat produced by electrical current concentrated at the sitewhere cutting is desired. In the absence of electrical energy, thedevice is capable of manipulating or mechanically dissecting bodytissue. Compared to conventional paddle electrodes, cutting efficiencyis improved by greater concentration of current in the tissues. Tissuethermal damage is reduced by elimination of current dispersed away fromthe cutting edge. This is accomplished by disposing a conducting memberalong the outer perimeter of a non-conductive support member. In thepreferred embodiment the conducting member comprises a thin, wireelectrode. The support member gives the wire electrode additionalsupport, strength, and rigidity which will allow for better cutting. Therigidity provided by the non-conducting support member allows thesurgeon better handling in positioning the device and guiding the deviceto cut along a precise path. Furthermore, with the electrical energy tothe conducting member on or off, the support member allows sufficientmechanical strength to manipulate or mechanically dissect body tissue.

The support member is generally of a shape and length suitable tocutting body tissue and may be embodied as a paddle shape with two majorsurface areas and a width dimension. The support member has a peripheraledge that is sufficiently thin to allow efficient cutting, but thickenough to ensure sufficient strength in the support member. The supportmember is preferably composed of a rigid, thermally stable,non-conductive material. Thus, the support member retains its strengthand utility when exposed to the heat produced by electrical energypassing through the supported conducting member and the adjacent tissue.Furthermore, the support member does not conduct electrical energy,hence electrical energy is not conducted through the major surface areasof the support member, only along the peripheral edge where theconducting member is disposed. Consequently, electrical energy is onlyapplied where the conducting member comes into contact with the bodytissue. In a preferred embodiment, the support member is composed of anyof a variety of ceramic substrates or plastics commonly known in the artbut can be made of any other suitable rigid, non-conductive material.

The electrode embodied in the present invention may include a handle forits manipulation by a surgeon or it may include an adaptable connectoron its proximal end which inserts into any of the common surgicalelectrode handles known in the industry to achieve an electricalconnection to the generator through the handle. The support memberextends from the distal end of the handle or the adaptable connector.The conducting member may be disposed along a portion of or to theentire exposed peripheral edge of the support member. Those skilled inthe art will recognize that many design configurations are possible byaltering the shape of the support member and the placement of theconducting member along at least a portion of the peripheral edge of thesupport member. Although such configurations may result in differentmethods of handling the device due to different shapes and differentpoints of contact of electrical energy, such variations do not departfrom the spirit and scope of the claimed invention.

Connection between the conducting member and an electrosurgicalgenerator is effectuated through the use of a conventional connectingwire or any other suitable means. The connecting wire is of a typesuitable for the conduction of high frequency electrical current, and ispreferably insulated. The electrosurgical generator is of a typecommonly used in the industry for transmitting high frequency electricalenergy during electrosurgical operations. In the course of operation,the electrosurgical generator produces a high frequency energy which istransmitted through the connecting wire to the conducting member. Thesurgeon then guides the conducting member to the specified area of bodytissue where the incision is to occur.

BRIEF DESCRIPTION OF THE DRAWINGS

To better understand the invention, a more particular description of theinvention will be rendered by reference to the appended drawings. Thesedrawings only provide information concerning typical embodiments of theinvention and are not to be considered limiting of its scope. Theinvention will be described and explained with additional specificityand detail through the use of the accompanying drawings, in which:

FIG. 1 is a perspective view of one embodiment of the electrosurgicalcutting device of the present invention;

FIG. 2 is a side view illustrating one embodiment of the electrosurgicalcutting device of the present invention showing the thickness of thesupport member and the placement of the conducting member along itsperipheral edge;

FIG. 3 is a side view of one embodiment of the electrosurgical cuttingdevice of the present invention showing the obverse, or reverse surfacearea of the support member;

FIG. 4 is an enlarged sectional view of the support member along line4--4 of FIG. 3;

FIGS. 5 and 6 are side views of alternative embodiments of theelectrosurgical cutting device with the conducting member encompassingadditional fill material other than the support member;

FIG. 7 is a side view of an embodiment of the electrosurgical cuttingdevice with a portion of the conducting member (shown in phantom lines)passing internally through the support member; and

FIG. 8 is a perspective view of an embodiment of the electrosurgicalcutting device with the support member extending from the handle.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference is now made to the figures wherein like parts are referred toby like numerals throughout. With reference to FIGS. 1, 2, and 3, thereis illustrated an electrosurgical cutting device 10 of the presentinvention. The cutting device 10 may be used as the active outlet of amonopolar circuit. The cutting device 10 comprises a support member 12composed of a strong, non-conductive material and a conducting member14. The conducting member 14 is preferably embodied as a wire electrodeand primary consideration is given to this embodiment in thespecification. However, it is understood, and those skilled in the artwill recognize, that other embodiments of the conducting member 14 suchas conductive materials in the form of deposits, etchings, or sprayswould be included within the scope of the is present invention.Preferably the material for the support member 12 is thermally stable sothat the support member 12 will be unaffected by the heat produced byelectrical energy passing through the conducting member 14. The materialis preferably from any one of a variety of ceramic substrates commonlyknown and used in the art but can be made of any other suitable materialsuch as plastic. The support member 12 may be configured in variousshapes suitable for cutting body tissue, including paddle shapes similarto conventional paddle electrodes with an obverse side, reverse side,width dimension, and a peripheral edge 16. Optionally, the supportmember 12 may also be configured in a variety of knife blade or scalpelshapes such as shown in FIGS. 7 and 8. The support member 12 isconfigured with a thin peripheral edge 16 with the conducting member 14disposed thereon, yet has sufficient mechanical strength to permit coldor mechanical dissection, separating and manipulating the body tissuewithout conduction of electrical energy. There is sufficient space onthe peripheral edge 16 to receive the conducting member 14. Optionally,the support member 12 may be formed with a groove 15 along theperipheral edge 16 in which the conducting member 14 is securely seatedas shown in FIG. 4.

The conducting member 14 is separate and distinct from the supportmember 12 and is composed of a material which is suitable to conducthigh frequency electrical energy for cutting body tissue. In a preferredembodiment, the conducting member 14 is composed of tungsten orstainless steel. The conducting member 14 is secured to the peripheraledge 16 of the support member 12, such that the surgeon can easily guidethe conducting member 14 to the position of desired contact with thebody tissue.

In the preferred embodiment depicted in FIGS. 1-3, the conducting member14 is embodied as a wire loop electrode with a wire forming a looparound the support member 12. In the preferred embodiment, theconducting member 14 is disposed along the entire exposed peripheraledge 16. However, those skilled in the art will recognize that a varietyof configurations and embodiments are possible. For example, as shown inFIGS. 5 and 6, the loop formed by the conducting member 14 may encompassthe support member 12 as well as some other fill material, such as air.The conducting member 14 may only be partially disposed along theperipheral edge 16, see FIGS. 7 and 8. In FIG. 7 the conducting member14 is partially disposed along the peripheral edge 16 and a portion ofthe conducting member 14 is internal to the support member 12. In FIG.8, the conducting member 14 the support member 12 is embodied in ascalpel shape and the conducting member 14 is disposed only along theleading edge of the support member 12. These configurations areillustrative of a variety of embodiments which are possible withoutdeparting from the scope of the invention.

A typical practice in the art is to have the conducting member 14attached to one end of a conducting adaptable connector 20. Theadaptable connector 20 is engageable with a handle 26, and electricalenergy is transmitted from the electrosurgical generator 22 through thehandle 26 and adaptable connector 20 to the conducting member 14. FIG. 1illustrates disposition of the handle 26 and adaptable connector 20 whendisposed in electrical communication.

As illustrated in FIG. 1, support member 12 and conducting member 14extend from the distal end of a conducting adaptable connector 20. Theadaptable connector 20 serves two purposes. It engages a source forelectrical energy from some conductive carrier such as theelectrosurgical generator 22 and transmits the electrical energy to theconducting member 14. It also permits attachment of the support member12 and conducting member 14 to a handle 26 to facilitate hand-heldmanipulation of the cutting device 10. The adaptable connector 20 is ofa configuration commonly known in the industry and its proximal end isinsertable into a receiving handle 26 which is also commonly known inthe industry.

The handle 26 receives in mechanical engagement the adaptable connector20 and accommodates the communication of electrical energy through aconnecting wire 18 which exits out the proximal end of the handle 26 andconnects to an electrosurgical generator 22. FIG. 1 shows the preferredembodiment of the invention in which the handle 26 is shown with aninterior cavity 17 for receiving the connecting wire 18.

The connecting wire 18 connects to the electrosurgical generator 22 andpreferably enters in the proximal end or midsection of the handle 26 andpasses into the interior cavity 17 of the handle 26, along alongitudinal axis of the handle 26. The connecting wire 18 electricallyengages the adaptable connector 20. The connecting wire 18 is insulatedand capable of carrying high frequency electrical energy to theconducting member 14 through the adaptable connector 20. In a preferredembodiment, the connecting wire 18 exiting from the electrosurgicalgenerator 22 is shielded within a cable 24 suitable for protecting theconnecting wire 18.

The electrosurgical generator 22 is of a type commonly known and used inthe industry, and has an adjustable output of high frequency electricalenergy. By controlling the output of the electrosurgical generator 22,the operator or surgeon is able to transmit sufficient high frequencyelectrical energy through the connecting wire 18 to the adaptableconnector 20 and to the conducting member 14 to enable the conductingmember 14 to cut body tissue.

Those skilled in the art will recognize that many other embodiments arepossible without departing from the scope of the invention. Forinstance, rather than using an adaptable connector 20, the connectingwire 18 may connect directly to the conducting member 14. An embodimentmay also forgo the use of an adaptable connector 20 and have the supportmember 12 and conducting member 14 extend from the distal end of ahandle 26 as seen in FIG. 8. In such an embodiment the handle 26 wouldhave means for conducting electrical energy from an electrosurgicalgenerator 22 to the conducting member 14.

It should be appreciated that the apparatus of the present invention iscapable of being incorporated in the form of a variety of embodiments,only a few of which have been illustrated and described above. Theinvention may be embodied in other forms without departing from itsspirit or essential characteristics. The described embodiments are to beconsidered in all respects only as illustrative and not restrictive andthe scope of the invention is, therefore, indicated by the appendedclaims rather than by the foregoing description. All changes which comewithin the meaning and range of equivalency of the claims are to beembraced within their scope.

What is claimed and desired to be secured by United States letters patent is:
 1. An electrosurgical cutting device for communicating electrically with an electrosurgical generator for use in a monopolar circuit comprising:a non-conductive support member having a peripheral edge; and a conducting member, distinct from said support member, configured to function as an active outlet in a monopolar circuit for electrosurgical cutting and disposed along at least a portion of the peripheral edge of said support member, said conducting member configured to communicate electrically with only one pole of the electrosurgical generator to receive high frequency electrical energy from the electrosurgical generator, wherein said conducting member forms a wire loop electrode with said support member filling the center of the loop.
 2. The electrosurgical cutting device of claim 1 wherein said wire loop electrode comprises a tungsten wire.
 3. The electrosurgical cutting device of claim 1 wherein said wire loop electrode comprises a stainless steel wire.
 4. The electrosurgical cutting device of claim 1 wherein said support member is composed of thermally stable material.
 5. The electrosurgical cutting device as in claim 1 wherein said support member is shaped in the form of a paddle with an obverse side, a reverse side, and peripheral edge.
 6. The electrosurgical cutting device of claim 1 wherein said support member is composed of ceramic material.
 7. The electrosurgical cutting device as in claim 1 wherein said support member is configured to allow the manipulation of body tissue in the absence of electrical energy to said conducting member.
 8. The electrosurgical cutting device of claim 1 wherein said support member is configured with a groove along at least a portion of the peripheral edge of said support member and said conducting member is seated in the groove.
 9. The electrosurgical cutting device of claim 1 further comprising an adaptable connector, said adaptable connector having a proximal and distal end, said support member extending from the distal end of said adaptable connector.
 10. The electrosurgical cutting device of claim 9 wherein said adaptable connector is configured to engage a handle in electrical and mechanical engagement to facilitate manual manipulation.
 11. An electrosurgical cutting device for communicating electrically with an electrosurgical generator for use in a monopolar circuit comprising:a non-conductive support member having a peripheral edge wherein said support member is configured with a groove along at least a portion of the peripheral edge of said support member; a conducting member, distinct from said support member, configured to function as an active outlet in a monopolar circuit for electrosurgical cutting and disposed along at least a portion of the peripheral edge of said support member, wherein said conducting member is seated in the groove; and an adaptable connector in electrical communication with said conducting member, said adaptable connector having a proximal and distal end, said support member extending from the distal end of said adaptable connector, wherein said adaptable connector is configured to be in electrical communication with only one pole of the electrosurgical generator to receive high frequency electrical energy from the electrosurgical generator.
 12. The electrosurgical device of claim 11 further comprising a handle configured to receive in electrical and mechanical engagement the proximal end of said adaptable connector.
 13. The electrosurgical device of claim 12 further comprising a connecting wire which passes through the interior of said handle and allows said adaptable connector to electronically communicate with the electrosurgical generator, thereby allowing the electrosurgical generator to transmit high frequency electrical energy through said adaptable connector to said conducting member to enable said conducting member to cut body tissue.
 14. The electrosurgical device of claim 11 wherein said support member is composed of thermally stable material.
 15. The electrosurgical device of claim 11 wherein said support member is configured to allow the manipulation of body tissue in the absence of electrical energy to said conducting member.
 16. The electrosurgical cutting device of claim 11 wherein a portion of said conducting member is internal to said support member.
 17. The electrosurgical cutting device of claim 11 wherein said conducting member comprises a wire electrode.
 18. An electrosurgical cutting device for communicating electrically with an electrosurgical generator for use in a monopolar circuit comprising:a handle having a proximal end and a distal end; a non-conductive, thermally stable support member extending from the distal end of said handle, said support member having a peripheral edge, said support member being configured to allow the manipulation of body tissue; and a conducting member, distinct from said support member, extending from said handle and configured to function as an active outlet in a monopolar circuit for electrosurgical cutting and, said conducting member disposed along at least a portion of the peripheral edge of said support member, said conducting member configured to communicate electrically with only one pole of the electrosurgical generator to receive high frequency electrical energy from the electrosurgical generator, wherein said conducting member forms a wire loop electrode with said support member filling the center of the loop.
 19. The electrosurgical device of claim 18 further comprising a connecting wire for contecting said electrosurgical generator electrically with said conducting member.
 20. The electrosurgical device of claim 18 wherein said support member is configured with a groove along at least a portion of the peripheral edge of said support member and said conducting member is seated in the groove.
 21. An electrosurgical cutting device for communicating electrically with an electrosurgical generator for use in a monopolar circuit comprising:a non-conductive support member having a peripheral edge; and a conducting member, distinct from said support member, configured to function as an active outlet in a monopolar circuit for electrosurgical cutting and disposed along at least a portion of the peripheral edge of said support member, said conducting member configured to communicate electrically with only one pole of the electrosurgical generator to receive high frequency electrical energy from the electrosurgical generator, wherein a portion of said conducting member is completely enclosed within said support member.
 22. The electrosurgical cutting device of claim 21 wherein said conducting member comprises a wire electrode.
 23. The electrosurgical cutting device of claim 21 wherein said support member is composed of thermally stable material.
 24. The electrosurgical cutting device of claim 21 wherein said support member is composed of ceramic material.
 25. The electrosurgical cutting device of claim 21 wherein said support member is configured with a groove along at least a portion of the peripheral edge of said support member and said conducting member is seated in the groove. 